package com.wc.alorithm_luogu.P1423;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2023/4/20 12:07
 * @description https://www.luogu.com.cn/problem/P1423
 * 小玉在游泳
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        // 总共需要游泳的距离
        double total = sc.nextDouble();
        // 每次的系数
        double vector = 0.98;
        // 步数
        int step = 0;
        // 下一次能游泳多少的距离
        double nextStep = 2;
        // 当前游泳的总数
        double sum = 0;

        while (sum < total) {
            sum += nextStep;
            nextStep *= vector;
            step++;
        }

        System.out.println(step);
    }
}
